Ruby - GPS Bricklet 2.0

This is the description of the Ruby API bindings for the GPS Bricklet 2.0. General information and technical specifications for the GPS Bricklet 2.0 are summarized in its hardware description.

An installation guide for the Ruby API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (example_simple.rb)

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#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_gps_v2'

include Tinkerforge

HOST = 'localhost'
PORT = 4223
UID = 'XYZ' # Change XYZ to the UID of your GPS Bricklet 2.0

ipcon = IPConnection.new # Create IP connection
gps = BrickletGPSV2.new UID, ipcon # Create device object

ipcon.connect HOST, PORT # Connect to brickd
# Don't use device before ipcon is connected

# Get current coordinates as [latitude, ns, longitude, ew]
coordinates = gps.get_coordinates

puts "Latitude: #{coordinates[0]/1000000.0} °"
puts "N/S: #{coordinates[1]}"
puts "Longitude: #{coordinates[2]/1000000.0} °"
puts "E/W: #{coordinates[3]}"

puts 'Press key to exit'
$stdin.gets
ipcon.disconnect

Callback

Download (example_callback.rb)

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#!/usr/bin/env ruby
# -*- ruby encoding: utf-8 -*-

require 'tinkerforge/ip_connection'
require 'tinkerforge/bricklet_gps_v2'

include Tinkerforge

HOST = 'localhost'
PORT = 4223
UID = 'XYZ' # Change XYZ to the UID of your GPS Bricklet 2.0

ipcon = IPConnection.new # Create IP connection
gps = BrickletGPSV2.new UID, ipcon # Create device object

ipcon.connect HOST, PORT # Connect to brickd
# Don't use device before ipcon is connected

# Register coordinates callback
gps.register_callback(BrickletGPSV2::CALLBACK_COORDINATES) do |latitude, ns, longitude,
                                                               ew|
  puts "Latitude: #{latitude/1000000.0} °"
  puts "N/S: #{ns}"
  puts "Longitude: #{longitude/1000000.0} °"
  puts "E/W: #{ew}"
  puts ''
end

# Set period for coordinates callback to 1s (1000ms)
# Note: The coordinates callback is only called every second
#       if the coordinates has changed since the last call!
gps.set_coordinates_callback_period 1000

puts 'Press key to exit'
$stdin.gets
ipcon.disconnect

API

All methods listed below are thread-safe.

Basic Functions

BrickletGPSV2::new(uid, ipcon) → gps_v2
Parameters:
  • uid -- str
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

gps_v2 = BrickletGPSV2.new 'YOUR_DEVICE_UID', ipcon

This object can then be used after the IP Connection is connected (see examples above).

BrickletGPSV2#get_coordinates → [int, str, int, str]

Returns the GPS coordinates. Latitude and longitude are given in the DD.dddddd° format, the value 57123468 means 57.123468°. The parameter ns and ew are the cardinal directions for latitude and longitude. Possible values for ns and ew are 'N', 'S', 'E' and 'W' (north, south, east and west).

This data is only valid if there is currently a fix as indicated by #get_status.

The returned array has the values latitude, ns, longitude and ew.

BrickletGPSV2#get_status → [bool, int]

Returns if a fix is currently available as well as the, the number of satellites that are in view.

There is also a green LED on the Bricklet that indicates the fix status.

The returned array has the values has_fix and satellites_view.

BrickletGPSV2#get_altitude → [int, int]

Returns the current altitude and corresponding geoidal separation.

Both values are given in cm.

This data is only valid if there is currently a fix as indicated by #get_status.

The returned array has the values altitude and geoidal_separation.

BrickletGPSV2#get_motion → [int, int]

Returns the current course and speed. Course is given in hundredths degree and speed is given in hundredths km/h. A course of 0° means the Bricklet is traveling north bound and 90° means it is traveling east bound.

Please note that this only returns useful values if an actual movement is present.

This data is only valid if there is currently a fix as indicated by #get_status.

The returned array has the values course and speed.

BrickletGPSV2#get_date_time → [int, int]

Returns the current date and time. The date is given in the format ddmmyy and the time is given in the format hhmmss.sss. For example, 140713 means 14.05.13 as date and 195923568 means 19:59:23.568 as time.

The returned array has the values date and time.

BrickletGPSV2#get_satellite_system_status(satellite_system) → [[int, int, ...], int, int, int, int]
Parameters:satellite_system -- int

Returns the

  • satellite numbers list (up to 12 items)
  • fix value,
  • PDOP value,
  • HDOP value and
  • VDOP value

for a given satellite system. Currently GPS and GLONASS are supported, Galileo is not yet supported.

The GPS and GLONASS satellites have unique numbers and the satellite list gives the numbers of the satellites that are currently utilized. The number 0 is not a valid satellite number and can be ignored in the list.

The following constants are available for this function:

  • BrickletGPSV2::SATELLITE_SYSTEM_GPS = 0
  • BrickletGPSV2::SATELLITE_SYSTEM_GLONASS = 1
  • BrickletGPSV2::SATELLITE_SYSTEM_GALILEO = 2
  • BrickletGPSV2::FIX_NO_FIX = 1
  • BrickletGPSV2::FIX_2D_FIX = 2
  • BrickletGPSV2::FIX_3D_FIX = 3

The returned array has the values satellite_numbers, fix, pdop, hdop and vdop.

BrickletGPSV2#get_satellite_status(satellite_system, satellite_number) → [int, int, int]
Parameters:
  • satellite_system -- int
  • satellite_number -- int

Returns the current

  • elevation (0° - 90°),
  • azimuth (0° - 359°) and
  • SNR (0dB - 99dB)

for a given satellite and satellite system.

The satellite number here always goes from 1 to 32. For GLONASS it corresponds to the satellites 65-96.

Galileo is not yet supported.

The following constants are available for this function:

  • BrickletGPSV2::SATELLITE_SYSTEM_GPS = 0
  • BrickletGPSV2::SATELLITE_SYSTEM_GLONASS = 1
  • BrickletGPSV2::SATELLITE_SYSTEM_GALILEO = 2

The returned array has the values elevation, azimuth and snr.

Advanced Functions

BrickletGPSV2#restart(restart_type) → nil
Parameters:restart_type -- int

Restarts the GPS Bricklet, the following restart types are available:

Value Description
0 Hot start (use all available data in the NV store)
1 Warm start (don't use ephemeris at restart)
2 Cold start (don't use time, position, almanacs and ephemeris at restart)
3 Factory reset (clear all system/user configurations at restart)

The following constants are available for this function:

  • BrickletGPSV2::RESTART_TYPE_HOT_START = 0
  • BrickletGPSV2::RESTART_TYPE_WARM_START = 1
  • BrickletGPSV2::RESTART_TYPE_COLD_START = 2
  • BrickletGPSV2::RESTART_TYPE_FACTORY_RESET = 3
BrickletGPSV2#set_fix_led_config(config) → nil
Parameters:config -- int

Sets the fix LED configuration. By default the LED shows if the Bricklet got a GPS fix yet. If a fix is established the LED turns on. If there is no fix then the LED is turned off.

You can also turn the LED permanently on/off, show a heartbeat or let it blink in sync with the PPS (pulse per second) output of the GPS module.

If the Bricklet is in bootloader mode, the LED is off.

The following constants are available for this function:

  • BrickletGPSV2::FIX_LED_CONFIG_OFF = 0
  • BrickletGPSV2::FIX_LED_CONFIG_ON = 1
  • BrickletGPSV2::FIX_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletGPSV2::FIX_LED_CONFIG_SHOW_FIX = 3
  • BrickletGPSV2::FIX_LED_CONFIG_SHOW_PPS = 4
BrickletGPSV2#get_fix_led_config → int

Returns the configuration as set by #set_fix_led_config

The following constants are available for this function:

  • BrickletGPSV2::FIX_LED_CONFIG_OFF = 0
  • BrickletGPSV2::FIX_LED_CONFIG_ON = 1
  • BrickletGPSV2::FIX_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletGPSV2::FIX_LED_CONFIG_SHOW_FIX = 3
  • BrickletGPSV2::FIX_LED_CONFIG_SHOW_PPS = 4
BrickletGPSV2#set_sbas_config(sbas_config) → nil
Parameters:sbas_config -- int

If SBAS is enabled, the position accuracy increases (if SBAS satellites are in view), but the update rate is limited to 5Hz. With SBAS disabled the update rate is increased to 10Hz.

By default SBAS is enabled and the update rate is 5Hz.

The following constants are available for this function:

  • BrickletGPSV2::SBAS_ENABLED = 0
  • BrickletGPSV2::SBAS_DISABLED = 1

New in version 2.0.2 (Plugin).

BrickletGPSV2#get_sbas_config → int

Returns the SBAS configuration as set by #set_sbas_config

The following constants are available for this function:

  • BrickletGPSV2::SBAS_ENABLED = 0
  • BrickletGPSV2::SBAS_DISABLED = 1

New in version 2.0.2 (Plugin).

BrickletGPSV2#get_api_version → [int, int, int]

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

BrickletGPSV2#get_response_expected(function_id) → bool
Parameters:function_id -- int

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by #set_response_expected. For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See #set_response_expected for the list of function ID constants available for this function.

BrickletGPSV2#set_response_expected(function_id, response_expected) → nil
Parameters:
  • function_id -- int
  • response_expected -- bool

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BrickletGPSV2::FUNCTION_RESTART = 6
  • BrickletGPSV2::FUNCTION_SET_FIX_LED_CONFIG = 9
  • BrickletGPSV2::FUNCTION_SET_COORDINATES_CALLBACK_PERIOD = 11
  • BrickletGPSV2::FUNCTION_SET_STATUS_CALLBACK_PERIOD = 13
  • BrickletGPSV2::FUNCTION_SET_ALTITUDE_CALLBACK_PERIOD = 15
  • BrickletGPSV2::FUNCTION_SET_MOTION_CALLBACK_PERIOD = 17
  • BrickletGPSV2::FUNCTION_SET_DATE_TIME_CALLBACK_PERIOD = 19
  • BrickletGPSV2::FUNCTION_SET_SBAS_CONFIG = 27
  • BrickletGPSV2::FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletGPSV2::FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletGPSV2::FUNCTION_RESET = 243
  • BrickletGPSV2::FUNCTION_WRITE_UID = 248
BrickletGPSV2#set_response_expected_all(response_expected) → nil
Parameters:response_expected -- bool

Changes the response expected flag for all setter and callback configuration functions of this device at once.

BrickletGPSV2#get_spitfp_error_count → [int, int, int, int]

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

The returned array has the values error_count_ack_checksum, error_count_message_checksum, error_count_frame and error_count_overflow.

BrickletGPSV2#set_bootloader_mode(mode) → int
Parameters:mode -- int

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

  • BrickletGPSV2::BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletGPSV2::BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletGPSV2::BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletGPSV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletGPSV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BrickletGPSV2::BOOTLOADER_STATUS_OK = 0
  • BrickletGPSV2::BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletGPSV2::BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletGPSV2::BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletGPSV2::BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletGPSV2::BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickletGPSV2#get_bootloader_mode → int

Returns the current bootloader mode, see #set_bootloader_mode.

The following constants are available for this function:

  • BrickletGPSV2::BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletGPSV2::BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletGPSV2::BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletGPSV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletGPSV2::BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletGPSV2#set_write_firmware_pointer(pointer) → nil
Parameters:pointer -- int

Sets the firmware pointer for #write_firmware. The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

BrickletGPSV2#write_firmware(data) → int
Parameters:data -- [int, int, ..61x.., int]

Writes 64 Bytes of firmware at the position as written by #set_write_firmware_pointer before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

BrickletGPSV2#set_status_led_config(config) → nil
Parameters:config -- int

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

  • BrickletGPSV2::STATUS_LED_CONFIG_OFF = 0
  • BrickletGPSV2::STATUS_LED_CONFIG_ON = 1
  • BrickletGPSV2::STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletGPSV2::STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletGPSV2#get_status_led_config → int

Returns the configuration as set by #set_status_led_config

The following constants are available for this function:

  • BrickletGPSV2::STATUS_LED_CONFIG_OFF = 0
  • BrickletGPSV2::STATUS_LED_CONFIG_ON = 1
  • BrickletGPSV2::STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletGPSV2::STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletGPSV2#get_chip_temperature → int

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

BrickletGPSV2#reset → nil

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

BrickletGPSV2#write_uid(uid) → nil
Parameters:uid -- int

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

BrickletGPSV2#read_uid → int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

BrickletGPSV2#get_identity → [str, str, str, [int, int, int], [int, int, int], int]

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

The returned array has the values uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

BrickletGPSV2#register_callback(callback_id) { |param [, ...]| block } → nil
Parameters:callback_id -- int

Registers the given block with the given callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickletGPSV2#set_coordinates_callback_period(period) → nil
Parameters:period -- int

Sets the period in ms with which the ::CALLBACK_COORDINATES callback is triggered periodically. A value of 0 turns the callback off.

The ::CALLBACK_COORDINATES callback is only triggered if the coordinates changed since the last triggering.

The default value is 0.

BrickletGPSV2#get_coordinates_callback_period → int

Returns the period as set by #set_coordinates_callback_period.

BrickletGPSV2#set_status_callback_period(period) → nil
Parameters:period -- int

Sets the period in ms with which the ::CALLBACK_STATUS callback is triggered periodically. A value of 0 turns the callback off.

The ::CALLBACK_STATUS callback is only triggered if the status changed since the last triggering.

The default value is 0.

BrickletGPSV2#get_status_callback_period → int

Returns the period as set by #set_status_callback_period.

BrickletGPSV2#set_altitude_callback_period(period) → nil
Parameters:period -- int

Sets the period in ms with which the ::CALLBACK_ALTITUDE callback is triggered periodically. A value of 0 turns the callback off.

The ::CALLBACK_ALTITUDE callback is only triggered if the altitude changed since the last triggering.

The default value is 0.

BrickletGPSV2#get_altitude_callback_period → int

Returns the period as set by #set_altitude_callback_period.

BrickletGPSV2#set_motion_callback_period(period) → nil
Parameters:period -- int

Sets the period in ms with which the ::CALLBACK_MOTION callback is triggered periodically. A value of 0 turns the callback off.

The ::CALLBACK_MOTION callback is only triggered if the motion changed since the last triggering.

The default value is 0.

BrickletGPSV2#get_motion_callback_period → int

Returns the period as set by #set_motion_callback_period.

BrickletGPSV2#set_date_time_callback_period(period) → nil
Parameters:period -- int

Sets the period in ms with which the ::CALLBACK_DATE_TIME callback is triggered periodically. A value of 0 turns the callback off.

The ::CALLBACK_DATE_TIME callback is only triggered if the date or time changed since the last triggering.

The default value is 0.

BrickletGPSV2#get_date_time_callback_period → int

Returns the period as set by #set_date_time_callback_period.

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the #register_callback function of the device object. The first parameter is the callback ID and the second parameter is a block:

gps_v2.register_callback BrickletGPSV2::CALLBACK_EXAMPLE, do |param|
  puts "#{param}"
end

The available constants with inherent number and type of parameters are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

BrickletGPSV2::CALLBACK_PULSE_PER_SECOND

This callback is triggered precisely once per second, see PPS.

The precision of two subsequent pulses will be skewed because of the latency in the USB/RS485/Ethernet connection. But in the long run this will be very precise. For example a count of 3600 pulses will take exactly 1 hour.

BrickletGPSV2::CALLBACK_COORDINATES
Parameters:
  • latitude -- int
  • ns -- str
  • longitude -- int
  • ew -- str

This callback is triggered periodically with the period that is set by #set_coordinates_callback_period. The parameters are the same as for #get_coordinates.

The ::CALLBACK_COORDINATES callback is only triggered if the coordinates changed since the last triggering and if there is currently a fix as indicated by #get_status.

BrickletGPSV2::CALLBACK_STATUS
Parameters:
  • has_fix -- bool
  • satellites_view -- int

This callback is triggered periodically with the period that is set by #set_status_callback_period. The parameters are the same as for #get_status.

The ::CALLBACK_STATUS callback is only triggered if the status changed since the last triggering.

BrickletGPSV2::CALLBACK_ALTITUDE
Parameters:
  • altitude -- int
  • geoidal_separation -- int

This callback is triggered periodically with the period that is set by #set_altitude_callback_period. The parameters are the same as for #get_altitude.

The ::CALLBACK_ALTITUDE callback is only triggered if the altitude changed since the last triggering and if there is currently a fix as indicated by #get_status.

BrickletGPSV2::CALLBACK_MOTION
Parameters:
  • course -- int
  • speed -- int

This callback is triggered periodically with the period that is set by #set_motion_callback_period. The parameters are the same as for #get_motion.

The ::CALLBACK_MOTION callback is only triggered if the motion changed since the last triggering and if there is currently a fix as indicated by #get_status.

BrickletGPSV2::CALLBACK_DATE_TIME
Parameters:
  • date -- int
  • time -- int

This callback is triggered periodically with the period that is set by #set_date_time_callback_period. The parameters are the same as for #get_date_time.

The ::CALLBACK_DATE_TIME callback is only triggered if the date or time changed since the last triggering.

Constants

BrickletGPSV2::DEVICE_IDENTIFIER

This constant is used to identify a GPS Bricklet 2.0.

The #get_identity() function and the ::CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletGPSV2::DEVICE_DISPLAY_NAME

This constant represents the human readable name of a GPS Bricklet 2.0.